Protective agent for meta styrene



- Patented Feb. 7,1933

UNITED STATES PATENT OFFICE HAROLD J. BARRETT, OF WILMINGTON, ANDEMMETTE I. IZARD, OF ELSMERE, DELA- WARE, ASEIZGNOBS TO E. I. DU PONT DENEMOURS & COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE vPROTECTIVE AGENT FOR META ST'YRENE Io Drawing.

This invention relates to. meta styrene. More particularly it relates tocompositions containin meta styrene. Still more specifically it re atesto the prevent of the checking and deterioration of meta styrene andcompositions containing it.

Meta styrene has many properties which make it desirable for use incoatin compositions. It is soluble in relatively 0 ea solvents and canbe applied as a protective ish in fairly concentrated solutions.Moreover, films of meta styrene are colorless, have satisfactory colorstability, and have excellent water resistance. The durability of thesefilms is unsatisfactory, however, due to the fact that after aging thefilms become brittle and develop checks or crowfoot cracks. Although theuse of plasticizers retards this cracln'ng, plasticizers do not overcomethe cracking entirely, and if used in too great quantity producethermoplastic films.

An object of this invention is to improve positions containing metastyrene. Other objects of the invention will become apparent as thedescription proceeds.

These objects are accomplished, generally speaking, by incorporatingwith the meta styrene or with the composition containing meta styrene asmall amount of certain or ganic nitrogen compounds. Amino com- .pounds,imino compounds, guanido comto be especially effective for this purpose.The use of 1% of the protective agent, based on the weight of metastyrene, appears to be sufiicient. The use of higher percentages of theprotective agent does not secure a sufiicient increase in durabilityover the use of 1% to warrant the use of larger amounts. Percentagesless than one percent also give useful results. 1

Thefollowing examples are illustrative of the durability of meta styreneand of compounds, and their derivatives have proved Application nledSeptemlier 13, 1980. Serial No. 481,800.

the invention but are not to be deemed in any sense limitative.

Example 1 When this lacquer was sprayed on steel panels it gave filmswhich were 1.4 times as durable, based on the number of days agingbefore cracks developed, as films prepared from a similar lacquercontaining no anihne.

Ewample II The substitution of di-o-tolyl-guanidine for the aniline inthe lacquer described in IIlazample I gave a product of the same durav iity.

Example II I The use of nitroso-beta-naphthol in place of the aniline inExample Igave a lacquer whose films were about 1.4 times as durable asthe control.

Ewample IV Parts Meta styrene 32.0 Titanox 21.0 "Dibutyl phthalate 10.5Toluen 57.8 Xylene 29. 7 Dimethylaniline 0.32

Films of this enamel sprayed over under- .coated steel were twice asdurable as those of a similar enamel which contained no pro- I tectiveagent.

methylaniline in Example IV gave a product meta nitraniline,methylaniline, and ethyliwhich was twice as durable as the unprotectedenamel.

5 Ewample VI The use of diphenylamine in place of dimethylaniline inExample IV gave an enamel whose films were twice as durable as those ofthe untreated enamel.

In addition to the protective agents given in the examples just cited,the following materials were also found to improve the durability ofmeta styrene films: Diphenyl guanidine, di-beta-naphthylamine, phenEl-alha naphthylamine, phenyl beta nap thy amine, ,dipropylamine,diphenyl-beta-naphthylamine, meta nitraniline, methyl-aniline andethylidene aniline. An examination of the various amines tested willshow that primary, secondary, and tertiary amines are all represented.The term an amino compound as used in this specification is intended toinclude amino compounds, substituted amino compounds, etc. The examplesinclude both aliphatic and aromatic nitrogen compounds.

Nitrogen compounds may be used in the preparation of all types ofcompositions containing meta styrene. The use of amines has been foundto be particularlyefiective for the preparation of coating compositionsfrom meta styrene.

An advantage of this invention lies in the prolongation of the life ofmeta styrene and of compositions containing meta styrene. Anotheradvantage is the retardation of the cracking of meta styrene andcompositions containing it.

As many apparently widely difierent embodiments of this invention may bemade without departing from the spirit and scope thereof, it is to beunderstood that we do not limit ourselves to the specific embodimentsthereof except as defined in the appended claims.

We claim: 1 A composition comprising meta styrene and di-o-tolylguanidine;

2. A composition comprising 'meta styrene, a softener, anddi-o-tolyl-guanidine.

3. A composition comprising meta styrene, a softener, a solvent, anddi-o-tolylguamdine.

4. A composition comprising about 35 parts of meta styrene, about 10.5arts of dibutyl phthalate, about 100 parts 0 solvent, and about .35parts of di-o-tolyl-guanidine. 5. 'A composition comprising meta one andone of a group of compounds conslsting of aniline. di-o-tolyl-guanidine,nitroso-beta naphthol, dimethyl aniline, dibutylamine, diphenylamine,diphenyl guanidine, dibeta-naphthylamine, pheny 1- alpha naphthylamine,phenyl-beta-naphthylamine, dipropylamine, diphenyl-beta-naphthylamme,

dene

aniline.

In testimony whereof we afiix our signatures.

HAROLD J. BARRETT. EMMETTE F. IZABD.

